riscv: set -march and -mabi based on the Kconfig configuration
Use the new Kconfig entries to construct the ISA string for the -march
compiler flag. The -mabi compiler flag is selected based on the base
integer instruction set.
With this change, the C (compressed instructions) ISA extension is now
enabled for all boards with CONFIG_RISCV_ISA_C set. Buildman reports a
decrease in binary size of 71590 bytes.
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 8fb6a88..55d7c65 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -3,6 +3,26 @@
# Copyright (C) 2017 Andes Technology Corporation.
# Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ifeq ($(CONFIG_ARCH_RV64I),y)
+ ARCH_BASE = rv64im
+ ABI = lp64
+endif
+ifeq ($(CONFIG_ARCH_RV32I),y)
+ ARCH_BASE = rv32im
+ ABI = ilp32
+endif
+ifeq ($(CONFIG_RISCV_ISA_A),y)
+ ARCH_A = a
+endif
+ifeq ($(CONFIG_RISCV_ISA_C),y)
+ ARCH_C = c
+endif
+
+ARCH_FLAGS = -march=$(ARCH_BASE)$(ARCH_A)$(ARCH_C) -mabi=$(ABI)
+
+PLATFORM_CPPFLAGS += $(ARCH_FLAGS)
+CFLAGS_EFI += $(ARCH_FLAGS)
+
head-y := arch/riscv/cpu/start.o
libs-y += arch/riscv/cpu/